If you really want to disable MDS, I think possibly Diablosport will do it. But from what I have seen, none of the options like Range Technology, Tazer, etc... work.
If you're just looking to turn it off, you can prevent it from kicking in by turning on the gear limit or using tow/haul mode (both require doing so each time you drive the truck).
As for adjusting for tire size, AlfaOBD or the ProCal Snap seem to be the most popular options around here.